package com.tll.rpc.framework;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.net.ServerSocket;
import java.net.Socket;

/**
 * Created by tll on 2017/3/29.
 */
public class RpcFramework {
    /**
     * 暴露服务
     *
     * @param service 服务实现
     * @param port    服务端口
     * @throws Exception
     */
    public static void export(final Object service, int port) throws Exception {
        if (service == null) {
            throw new IllegalArgumentException("service instance is null");
        }
        if (port <= 0 || port > 65535) {
            throw new IllegalArgumentException("invalid port" + port);
        }
        System.out.println("Export service:" + service.getClass().getName() + "port:" + port);
        ServerSocket serverSocket = new ServerSocket(port);
        for (; ; ) {
            try {
                final Socket socket = serverSocket.accept();
                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        try {
                            try {
                                ObjectInputStream input = new ObjectInputStream(socket.getInputStream());
                                try {
                                    String methodName = input.readUTF();
                                    Class<?>[] parameterTypes = (Class<?>[]) input.readObject();
                                    Object[] arguments = (Object[]) input.readObject();
                                    ObjectOutputStream output = new ObjectOutputStream(socket.getOutputStream());
                                    try {
                                        Method method = service.getClass().getMethod(methodName, parameterTypes);

                                        Object result = method.invoke(service, arguments);

                                        output.writeObject(result);
                                    } catch (Throwable e) {
                                        output.writeObject(e);
                                    } finally {
                                        output.close();
                                    }
                                } finally {
                                    input.close();
                                }
                            } finally {
                                socket.close();
                            }

                        } catch (Exception e) {
                            e.printStackTrace();
                        }

                    }
                }).start();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * 引用服务
     * @param interfaceClass 接口类型
     * @param host 服务器主机名
     * @param port 服务器端口
     * @param <T>接口泛型
     * @return
     */

    @SuppressWarnings("unchecked")
    public static <T> T refer(final Class<T> interfaceClass, final String host, final int port) {
        if (interfaceClass == null) {
            throw new IllegalArgumentException("Interface class==null");
        } if (!interfaceClass.isInterface()) {
                throw new IllegalArgumentException("The" + interfaceClass.getName() + "must be interface class!");
            }  if (host == null || host.length() == 0) {
                    throw new IllegalArgumentException("host is null");}
                    if (port <= 0 || port > 65535) {
                        throw new IllegalArgumentException("invalid port" + port);}
                        System.out.println("Get remote service " + interfaceClass.getName() + " from server " + host + ":" + port);
                    return (T) Proxy.newProxyInstance(interfaceClass.getClassLoader(), new Class<?>[]{interfaceClass}, new InvocationHandler() {
                            @Override
                            public Object invoke(Object proxy, Method method, Object[] arguments) throws Throwable {
                                Socket socket = new Socket(host, port);
                                try {
                                    ObjectOutputStream output = new ObjectOutputStream(socket.getOutputStream());
                                    try {
                                        output.writeUTF(method.getName());
                                        output.writeObject(method.getParameterTypes());
                                        output.writeObject(arguments);
                                        ObjectInputStream input = new ObjectInputStream(socket.getInputStream());
                                        try {
                                            Object result = input.readObject();
                                            if (result instanceof Throwable) {
                                                throw (Throwable) result;
                                            }
                                            return result;
                                        } finally {
                                            input.close();
                                        }
                                    } finally {
                                        output.close();
                                    }
                                } finally {
                                    socket.close();
                                }
                            }
                        });
    }



}